Method of and apparatus for making bags



April 8, 1941., R. M. BELL METHOD OF AND APPARATUS FOR MAKING: BAGSFiled larch 7, 1940 3 Shuts-Shoat 1 April 1941- R. M. BELL "ETHOD OF ANDAPPARATUS FOR MAKING BAGS 3 Shoots-Shoot 2 Filad larch '1, 1940 April 8,1941. R. M. BELL IE'I'HOD OF AND APPARATUS FOR MAKING BAGS Filed larch7. 1940 3 Shoots-Sheet 3 Patented Apr. 8, 1941 METHOD OF AND APPARATUSFOR MAKING BAGS Raymond M. Bell, Wayne, Pa., assignorto Benjamin C.Betner Company, Devon, Pa., a corporation oi Delaware Application March7, 1940, Serial No. 322,716

4 Claims.

My invention relates to methods of and apparatus for making, fromwebbing, bags, liners,

, wrappers and the like, herein generically termed "bags" which aresealed, at least in part, by adhesive applied to the webbing from whichthe bags are made prior to detachment of the bags therefrom. I

In accordance with my invention, the webbing, of paper or other sheetmaterial, during feed thereof is passed adjacent a smooth, unpatterned,surface, preferably the periphery of a roll, coated with adhesive whichmay be a molten film-forming material, a hot-metal thermoplastic, or ofother kinds herein described; one face of the webbing is intermittentlypressed into contact with the coating on the surface by structureengaging its opposite face and whose webengaging surface is of a patternor configuration corresponding with the desired pattern of adhesive tobe transferred to the webbing from aforesaid coated surface.

My invention further resides in the methods of and apparatus for makingbags hereinafter described and claimed.

For an understanding of my invention, reference is had to theaccompanying drawings, in which:

Fig. l, in perspective, illustrates a preferred method and arrangementfor transferring adhesive to webbing;

Fig. 1a., in perspective, illustrates another method and arrangement fortransferring adhesive to webbing;

Fig. 2 diagrammatically illustrates the apparatus of Fig. 1 and abag-forming machine in combination;

Fig. 3 is a plan view of a portion of the web.- bing shown in Figs. 1,1a and 2;

Figs. 4, 4a, 5 and 6, in perspective, illustrate successive steps offormation from the webbing of Fig. 3 of the completed bag shown in Fig.6;

Figs. 7 and 8, in perspective, schematically illustrate arrangements forsealing bags; 7

Fig. 9 is a plan view of webbing to which has been applied patterns ofadhesive different from those of Fig. 3;

Fig. 10, in perspective, shows a pressure-applying tool utilizable intransfer to the webbing of the patterns of adhesive shown in Fig. 9;

Figs. 11, 12 and 13, in perspective, illustrate successive steps offorming and sealing the bottom of a bag made from the webbing of Fig. 9;

Figs. 14 to 18, in perspective, illustrate the formation in accordancewith my invention of various other types of bags.

Referring to Fig. 1, the webbing W may be of any sheet material suitablefor making bags; for example, it may be of paper, coated, impregnated,or otherwise treated to procure enhanced strength, resistance topenetration by moisture or grease, or to procure any other desiredcharacteristic; it may be any ordinary untreated paper; or it may besheet film, such as Cellophane or the like.

Webbing W is fed from roll R over the idler rolls 2, I, and over theintermediate member 3 whose raised web-engaging surface is, in thismodification, the substantially rectangular face of a bar or ridge 4extending axially of roll 3 and projecting outwardly from the peripherythereof.

Once for each revolution of member 3, the bar or projection 4, pressingagainst one face of the web, moves it from the position shown in Fig. 2to the position shown in Fig. 1, thus to effect contact of the oppositeface of the web with the roll 5. The periphery of roll 5 is coated withadhesive, maintained, when of hot-melt type, in molten state by heatapplied in any suitable manner; for example, the axle 6 of roll 5 may behollow to allow passage into the roll, from any suitable source, ofsteam of suitably high tempera'ture.

Each time the web W is pressed against roll 5 there is transferredthereto a pattern, stripe or band of adhesive corresponding with ordefined by the shape and extent of raised surface 4 of member 3, whichpattern, in Fig. 1, is a band or stripe S extending across web W.

The surface of the web pressed against roll 5 is cold or of roomtemperature, and so tends to chill the adhesive, when of the hot-melttype, which it contacts, with the result the adhesive more readilytransfers from. roll ii to the web.

The extent of feed of web W between aforesaid successive engagements ofthe bar 4 with the web depends, as will hereinafter appear, upon thelengths of the bags to be made and upon whether one or both ends of eachbag is or are to be closed by the adhesive transferred from roll 5.

The peripheral speed of the roll 5 should be sufficiently high to insurepresentation to web W for each of its successive contacts therewith ofan increment of coated surface other than the one against which web ,Wwas pressed during the last prior revolution of member 3. When the webis fed continuously, the peripheral speed of roll 5 should approximateor equal the linear speed of the web to avoid relative wiping motioncausing stringiness and irregularity of the pattern of adhesivetransferred to the web.

The adhesive coating on roll 5 is continuously replenished by transferthereto from the roll I which is to substantial extent submerged in'amass of adhesive in fluid state held in reservoir 8, and thereinmaintained in fluid state, when of hot-melt type, by any suitable sourceof heat, for example, an electric heater 9A, Fig. 2, connected to asuitable source of current by cord 9 and plug ID.

The adhesives employed preferably are of the type known as "hot-melt,and those known as of lacquer or solvent types.

A' suitable hot-melt adhesive comprises an ethyl-cellulose base, 5% to40%; a wax, such as Opal 10% to 50%; a natural or synthetic resin, 10%to 30%, and a chemical plasticiser, for example tricresylphosphate, 10%to 30%; it is comprised in the class known as Proxmelt.

There may be employed waxes which are themselves sticky; or waxesmodified by incorporation of a resin, such as paracoumarone resin,rosin, or a modified rosin; or, the wax may be modified to give itadhesive properties by means of natural rubber, polymerized butadiene orpolymerized isobutylene.

Suitable thermo sealing materials mayalso be made from the ethers' ofcellulose, alone, or with modifying agents. Cellulose esters such asnitrocellulose may be used with resins capable of inducingthermo-plasticity. Also, resins may be used alone or with modifyingagents. There may also be used suitable compositions made from thevarious resins derived from rosin, such as hydrogenerated rosin, andglycol and glycerol esters of rosin; also suitable molten film-formingagents from paracoumarone resins, shellac, polystyrene, and several ofthe resins derived from vinyl intermediates.

As a further specific operative example of molten film-forming materialsuitable for my process, there may be used the following composition:ethyl cellulose, 24 parts by weight; ester gum,

' phenol hardened, 16 parts by weight; dibutyl phthalate, 12 parts byweight; paraflln, 135 degrees, 22 parts; and fully hydrogenated cottonseed oil fatty acid, solid, 26 parts,

While the following description deals more particularly with hot-meltadhesives and adhesives consisting of molten film-forming materials. itshall be understood my invention is not I limited thereto and that otheradhesives may be employed so long as they be of types suited not only totransfer thereof to the webbing by the herein described method andapparatus, but suited also to such other steps, purposes and conditions,subsequent to transfer to the webbing, as may be imposed by practicalconsiderations.

Because the viscosity of such hot-melt adhes ves at temperatures forapplication to webbing W is high, as of the order of 2000 centipoises,it or other adhesives of too great viscosities or other characteristicsis or are not wholly and effectively satisfactorily transferred towebbing by and directly from a stencil or equivalent coated therewith.Moreover, with the conventional stencil arrangement, the impression rollover which the web passes becomes heated, as by and due to repeatedcontacts with the webbing of the stencil, if heated to suit the adhesiveemployed, and the webbing is heated to a temperature sufficiently highto preclude proper transfer of adwith my arrangement, as above stated,the relatively low temperature of the webbing facilitates transfer ofadhesive thereto, and its quick hardening thereon when of such type.

Reverting to Figs. 1 and 2, hot-melt adhesive. as it passes upwardly onthe surface of roll I, is uneven and stringy because of its aforesaidhigh viscosity; however, due to squeezing of the adhesive between therolls 5 and I, it is spread out or distributed to effect a smooth, evencoating on the periphery of roll 5, so to insure transfer to the webbingof patterns of adhesive which are consistently similar to each other andto the surface configuration of the presser member 4, and which patternsare free of ridges of adhesive and of areas covered with insuflicientadhesive or bare. The thickness of the adhesive, whatever its type,transferred to the webbing may be accurately controlled or predeterminedby adjustment, in any suitable manner, of the pressure between rolls 5and I.

The hot-melt so transferred directly to the inner face of the web due topressure on its outer face by member 4, solidifies almost instantly, sopermitting the webbing to be folded, rolled, or otherwise manipulated oroperated upon within a short time or at a short distance beyond theapplying roll 5; it may, for example, pass at once into a printing pressor to a bag-making machine. Solvents may be used with the hot-melt toimpart fluidity, but in such case the webbing, after application of theadhesive, may need to be passed through one or more drying chambersbefore it can be folded or otherwise operated upon; however, such use ofsolvents, so requiring drying chambers, is unnecessary when the hotmeltis transferred by and in accordance with the apparatus and methodsherein described.

In the modification shown in Fig. 1a, the rotating member 3 of Fig. 1 isreplaced by the reciprocating member 3A whose web-engaging face 4A isshaped to correspond with the desired pattern of adhesive to betransferred from roll 5 to the webbing W. The mechanism, not shown,which reciprocates the member 3A intermittently to cause face 4A topress the webbing against coated roll 5, is so timed with respect to thecontinuous or intermittent feed of web W that there is obtained thedesired spacing between the successive patterns of adhesive upon thewebbing. For making bags having single bands or stripes of adhesiveadjacent either their mouths and/or bottoms, the timing of member 3A issuch that the spacing between successive stripes S upon web Wsubstantially correspond with the length of a single bag blank; wheneach of the bags shall have a plurality of stripes of adhesive, themember 3A may either be replaced by one having a suitably differentlyshaped pressure member; i. e., one having a double blade extendingtransversely of the webbing; or the mechanism for operating member 3Amay be of such character that it operates it at proper times during feedof the web to efiect transfer of the adhesive in stripes which arealternately close together,

and widely spaced, generally as shown in Fig. 8 of Haskell Patent2,062,265.

Sharply to define the edges or boundaries of the patterns or stripes ofadhesive applied to the web, in avoidance of irregularities in theadhesive pattern at its edges as may otherwise occur because of theviscosity or other phoperty of the adhesive, it is desirable that theweb, after engagement thereof with the adhesively coated surface, shallnot too rapidly recede therefrom as the pressure member itself recedesfrom position corresponding with maximum pressure of the web againstthecoated surface. To this end, when the structure is of the characterillustrated in Figs. 1 and 2, the distance between the axes of rolls 3and 5, and the distance of the operative surface of member 4 from itsaxis of rotation or the extent of projection of member 4 beyond theperiphery of the roll 3, are so relatively chosen or designed to procuresufficiently slow recession of the web from the surface or roll 5. Whenthe structure is of the character fllustrated in Fig. 1a, the sameresult is obtainable by suitable construction of the cam or othermechanism which effects reciprocation of member 3A.

The webbing W, after transfer of the stripes S thereto, by mechanism ofFig, 1 or la,-may be rerolled on a storage roll for immediate or delayedtransport to a bag-making machine, or, and preferably, as shown in Fig.2, the webbing W, after leaving roll 5, continues its movement towardbag-making machine M, of any conventional type suited to make theparticular form of bag desired. In either case, and particularly theformer, the webbing, if of untreated stock, may, after solidification orsetting of adhesive stripes S, be subjected to any coating or treatingprocess to obtain enhanced strength, resistance to mois ture, or otherdesired characteristic, provided such treatment does not involvesubjection of the adhesive to physical or chemical effects adverselyaffecting its properties or effectiveness when subsequently heated forbag-sealing purposes; otherknives i I, i2 into successive tubular blanksB.

Each of blanks B in passing between the rolls i3 and it receives fromthe reciprocating stencil i5 9. stripe D (Fig. 4a) of adhesive over andagainst which the leading end of the tubular blank is bent bycooperation of the folding knife l5 with notch or recess IS in theperiphery of roll Id. The stencil i5 for each revolution of roll i3engages the coated periphery of roll 30 to receive a coating of glue,paste or other solvent-type of adhesive which it subsequently in therevolution applies to a blank B; roll 30 which is in continuous rotationdips below surface of the adhesive in reservoir 3 l. The adhesivetransferred from reservoir 3| and applied by stencil i5 is preferably ofaforesaid type and not of the hot-melt type.

"The banks B discharged beyond the rolls i3, it fall upon belt l'lwhich, in cooperation with belt l8, transfers the blanks to areceptacle, such as hopper l9, and, during transfer, between belts i1and IS, the folded bottom of each is held against the adhesive appliedby stencil 15' for a time sufficient to insure sealing of the bottom ofthe bag; during their transport by and between stripes S which arespaced longitudinally of the webbing, Fig. 3. The longitudinal marginsof the web W are shortly thereafter overlapped and joined by adhesive,preferably in a bag-making machine as previously described, to form alongitudinal seam A, Fig. 4, of a tube whose opposite sides may betucked in to form gusset or reentrant folds C, C, Fig. 4. The tubing iscut, as by knives Ii, l2, Fig. 2, to form individual bag blanks, Fig. 4.The stripe D, Fig. 4a, applied across one exterior face of the bottomportion of blank B, preferably within a bag-making machine, may be anysuitable solvent type of adhesive, or it may be of the hot-melt type, inwhich latter case it should be applied by an arrangement similar to thatshown in Figs. 1

. or 1a of which it is characteristic the transfer of adhesive iseffected not by a stencil, but by pressing the bag material against asmooth surface coated with hot-melt. When the adhesive applied at D isof the solvent type, the bottom of the blank B is substantially at oncefolded over stripe D, Fig. 5, and held in engagement for a length oftime to insure setting of the adhesive; when stripe D is of hot-melt,the bottom of the bag may be closed at any suitable time after theapplication of stripe D by folding the bag bottom and applying pressureand heat thereto. Such subsequent formation of the bottoms of the bagsmay be of advantage because they may be shipped fiat, and because itpermits formation of bags of somewhat different sizes from identicalblanks, so to suit the bags to the needs of a particular customer or forparticular materials or commodities to be enclosed in the bags, withoutneed to maintain on hand a large assortment of bags of different sizes.

The mouth of the individual bags, Fig. 6, may be sealed, after filling,by pressing together the sides of the bag above the filling andconcurrently applying heat thereto; for example, the mouth end of thebag may be fed between rolls 20, 2|, Fig. 7, either or both of themheated, or,

as shown in Fig. 8, the open end of the bag may.

be flattened between the plates or members 22, 23 either or both ofwhich may reciprocate, and either or both of which may be heated.

When both the bottom and mouth of the bag blank are to be sealed byhot-melt" adhesive transferred from roll 5, the member 3 may be providedwith an additional bar to provide, longitudinally of webbing W, pairs ofmore or less closely spaced stripes S of adhesive, one eventually toappear as a band within the mouth of one bag, and the other to appear asa band within the bottom-forming end of the succeeding blank formed fromthe webbing. In such case, each blank comprises a tubular section ofwebbing formed by adhesive joinder of the longitudinal margins of thewebbing and within which, at opposite ends thereof, there are encirclingbands or stripes of thermoplastic which can be reactivated byapplication of heat and joined to each other to form a seal bysubstantially concurrent application of pressure.

Although it usually is desirable that the stripe of thermoplasticapplied to the webbing should extend entirely thereacross, so to providewithin the mouth of each bag formed therefrom a band of adhesive whichis continuous, for at least some purposes, the stripe may bediscontinuous or extend only partly around the inner periphery of thebag blank; in such cases, the web-engaging surface 4 or 4A of theweb-actuating member 3 or 3A will be correspondingly modifled in shape.

When the bags to be made from the webbing W, Fig. 9, are of theso-called automatic" or self-opening type, the blade .or bar 4, Fig. 1,is replaced by the two bars 4a, 4b, Fig. 10, of suitably differentlengths to effect transfer from roll 5 to the webbing for eachrevolution of member 3 two stripes SI, S2, Fig. 9, of adhesive whicharein substantial alignment with each other transversely of the webbing.Before, or preferably after, application of a pair of stripes SI, S2,the webbing is slitted, as at E, E, to provide, upon severance of thewebbing at El, a flap F whose purpose will later appear in discussion ofFigs. 11 to 13.

The longitudinal margins of the webbing are adhesively joined at A,Figs. 11 to 13, to form a succession of tubular blanks whose oppositesides are tucked or folded in, in suitable manner, as by mechanism knownin the art, to form gusset or reentrant folds C. The leading end of eachtubular blank is in turn folded, as shown in Fig. 11, to provide four.bottom-forming panels F2, F3, F4 and F5, the last-named includingaforesaid flap F, defined by folding along lines Bf, Bf. To close andform the bag bottom, the panel F3 is moved from the position shown inFig. 11 toward and beyond the position shown in Fig. 12 to bring theunder face thereof into engagement with panels F2, F4 and to effectoverlying relation of the portions of stripes Si, S2 on the under faceof panel F3 upon the portions of stripes Si, S2 of adhesive on thepanels F2, F4; the panel F5 is thereafter folded from the position shownin Fig.- 12 to the position shown in Fig. 13 to effect engagement ofthat portion of stripe S2 on panel F2 with the portion of the samestripe on panel F5, and to effect engagement of that portion of stripeSI on panel F5 with the portion of "the same stripe on panel F4, andalso to effect engagement of flap F with that portion of stripe SI onflap F3 visible in Fig. 12. While the panels are so folded, Fig. 13,they are subjected to heat and pressure so to effect anadhesive-to-adhesive bond of panel F3 with panels F2 and F4., and anadhesive-to-adhesive bond between panel F5 and panels F2 and F4, and toeffect engagement of flap F with the adhesive on panels F2, F3 and F4.

If it is desired that the mouth of the bag, Fig. 13, also be providedwith a band of adhesive, suited to seal it after filling of the bag, themember 3, Fig. 10, may be provided with additional bar structuresuitably angularly spaced with respect to bars 4a, 4b to provide, inaddition to stripes SI, S2, continuous stripes, such as transversestrips S of Fig, 3.

As shown in Fig. 11, the adhesive stripes SI and S2 are continuous fromend to end, and especially so across the folds or fold lines Bf, Bf;these stripes being so applied in continuity, in the method or apparatusof either Fig. 1 or Fig. la, i. e. before the adhesively striped webbingis formed into a bag destined to be of the selfopening type, there areprevented the unavoidable gaps in the continuity of adhesive stripesformed adjacent the fold lines, such as Bf, Bf, which gaps heretoforehave been occasioned by the fact the adhesive stripes, generally likeSI, S2, are applied after the tube has been folded, as shown in Fig. 11,and is pinched at the fold lines Bf, Bf. In brief, by applying thestripes SI s2 in continuity, as appearing in Fig. 11, when firstapplying adhesive to the webbing, before formation thereof into a bag,there are avoided the aforesaid gaps which are occasioned by aforesaidlate application of the adhesive stripes during the formation of thebottom of the bag.

By transversely cutting the webbing, Fig. 3. along substantially themiddle of each stripe S, there are formed blanks, such as shown at B3 inFig. 14, each having along each of its longer margins a stripe S3 ofthermoplastic adhesive. The blank B3 is transversely folded, as shown atZ in Fig. 14, substantially midway of its length, to bring intooverlying relation those areas of the blank which, upon application ofheat and pressure thereto, form the side seams or seals G, G, Fig. 15

To make this type of bag, Fig. 15, though it is desirable that thestripes S extend entirely across the webbing, Fig, 3, it sufilces ifthey extend from one edge of the webbing to the center or fold line Z,or preferably at least to slight extent beyond it.

The severance of the webbing W to form the blanks B3 is effected afterhardening or setting of the adhesive S, but since this is a matter ofrelatively short time, as of seconds, the web W may be immediatelypassed from the roll 5, Fig. 1, to the knife or shearing device, such asH, i 2 of Fig. 2, which forms the blanks B3 by cutting transverselythrough the webbing along substantially aforesaid middle of the width ofthe successive stripes S.

The stripes S4 of adhesive, Figs. 14 and 15, which may be applied to thewebbing longitudinally thereof when it is desired to seal the mouths ofthe bags after filling, are preferably of hotmelt, and may be applied bya reciprocating pressure-applying member generally similar to that shownin Fig. 1a and which operates upon the web between successive feedingmovements thereof.

More generally stated, when the adhesive is applied to the webbing as atransverse stripe, Fig. 3, the feed of the web may be continuous, as inFigs. 1 and 2; but when the applied stripe of adhesive, such as S4, Fig.14, is to extend parallel to the direction of feed of the webbing, theweb should be at rest between successive movements of feed thereof whenpressed by a pressure-applying tool corresponding with member 3A of Fig.1a, against a plate or other structure coated with hot-melt;alternatively, the web may be in motion during transfer of hot-meltthereto provided that the pressing tool and the coated member are,during their engagement with the web, moving with it and atsubstantially the same speed. Otherwise, because of the viscouscharacter of the "hot-melt, the transfer is unsatisfactory and thepatterns are stringy, irregular, and non-uniform in appearance.

The bag shown in Fig. 16 may be made from the webbing striped as shownin Fig. 3 by folding its longitudinal margins into adhesive engagementwith each other to form longitudinal seam A; except that the sides ofthe tubular blank so formed are not folded or tucked in, it is similarto the blank B shown in Fig. 4. One end of the tubular blank B4 isfolded and flattened to form the bottom of the bag, generally in themanner shown in Figs. 4a and 5; the bottom may be held so folded byadhesive suitably applied, as at D, either manually or, Fig. 2, duringpassage of the webbing through mechanism suitable for makingthis type ofbag. The blanks B4 are so cut from the webbing, as by knives H, l2, Fig.2, that each of them has adjacent its mouth one of the internal bands orstripes S of thermoplastic adhesive which, at any time, after filling ofthe bag, may be reactivated by subjecting it to heat and pressure, as inFig. 7 or Fig. 8, to seal the mouth of the bag.

The blank B5 for making a square or gusseted bag, Figs. 17 and 18, is,before folding, similar to blank B3 of Fig. 14. After each blank, B5,Fig. 17, is cut from the web W, Fig. 3, it is first folded lengthwisealong the lines X, XI, Y, Yi, and then folded crosswise along the line Zto bring into engagement with each other the faces of theoutwardly-turned panels H, Fig. 18, coated with stripe or stripes S3 ofthermoplastic adhesive. The side seams J, J are formed by application ofheat and pressure to the outside faces of the pairs of panels H, H.

When it is desired to provide for sealing of the mouth of the bag B5,after filling thereof, each. of the blanks has adjacent and parallel toits opposite narrow edges a transverse band or stripe S it, preferablyof hot-melt, applied generally as described in connection with Figs. 1,1a and 2. Thus, when blank B5 is folded as shown in Fig. 18, the ends ofstripes 84 are joined at H so to form a continuous band or ring ofadhesive extending completely around the inside of the bag adjacent itsmouth, with the end portions of each stripe 54 extending half way acrossthe gusset fold C, i. e. to the inner edge of each panel H. Afterfilling of the bag, the mouth is sealed by flattening the top portion ofthe bag above the contents and applying heat and pressure thereto, forexample by an arrangement similar to that shown in Fig. '7 or 8, so

to unite with each stripe S4 its aforesaid end portions, and to unitethe two stripes S4 throughout their lengths between their said endportions.

From all the foregoing, it is evident that various other types of bags,and liners, wrappers and the like, as well may be formed from webbingprepared by transfer thereto of patterns of thermoplastic or otheradhesive by arrangements of the characters of those exemplified by Figs.1, lo and 2; it is therefore to be understood my invention is notlimited to formation of bags or the like of the kinds specificallyillustrated and described, but is coextensive in scope with the appendedclaims.

I disclaim from the scope of the appended I claims those methods andmechanisms characterized by impression of adhesive on one face of theweb by pressure exerted on its opposite face by an uncoatedpressure-applying surface whose configuration and extent are differentfrom the configuration and extent of the applied adhesive.

Certain of the herein described bags and methads of producing them areclaimed in my divisional application, Serial Number 380,859, filedFebruary 27, 1941.

What I claim is:

l. A method of operating upon webbing for production of bags therefromwhich comprises feeding the webbing, coating an unpatterned surface withthermoplastic adhesive, intermittently pressing the webbing, atintervals spaced in the direction of its feed, between said unpatternedcoated surface and a patterned uncoated surface to effect transfer tothe webbing from said unpatterned coated surface of adhesive inpredeter-' adhesive thereon, feeding webbing adjacent said so-coatedsurface, and intermittently, at intervals spaced along it in thedirection of its feed, pressing the webbing by an uncoated surface intocontact-with the molten adhesive on said coated surface to effecttransfer thereof to the webbing in predetermined patterns correspondingin extent and configuration with said uncoated surface.

3. A method which comprises heating solid thermoplastic adhesive totemperature sufficient to transform it into molten state with high viscosity, spreading the viscous molten adhesive upon a surface attemperature sufficient to prevent substantialsolidification of theadhesive thereon, feeding adjacent said so-coated surface webbing fromwhich are to be produced bags having seals, intermittently, at intervalsspaced along it in the direction of its feed, pressing the webbing by anuncoated surface into contact with the molten adhesive on said coatedsurface to effect transfer thereof to the webbing in predeterminedpatterns corresponding in extent and configuration with said uncoatedsurface, and, after setting of the transferred adhesive, cutting andshaping the webbing to form bags each having exposed within it at leastpart of. one of said patterns of thermoplastic adhesive.1

4. The combination with mechanism for making bags from webbing and meansfor feeding the webbing thereto, of a roller adjacent the path of feedof the webbing and coated with molten viscous thermoplastic adhesive,means for heating said roller to maintain said adhesive molten, a memberhaving a web-engaging surface shaped to define the pattern of adhesivetransferred to said webbing, and means operating in timed relation tosaid web feeding means intermittently to press said surface of saidmember against one face of the Webbing to effect contact of the oppositeface thereof with the coating on said roller for transfer of moltenadhesive to the webbing in a series of patterns.

RAYMOND M. BELL.

